Note: Descriptions are shown in the official language in which they were submitted.
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Title: Apparatus, Systems and Methods for Collecting and Reclaiming
Anaesthetic Agents and for Removing Nitrous Oxide from Exhaust
Gases
Technical Field
[0002] Embodiments described herein relate to. apparatus, systems and
methods for collecting and/or reclaiming anaesthetic agents, and in
particular,
for reclaiming halogenated drugs from exhaust gases such as waste air
expelled by patients in operating rooms, as well as for removing other
substances from exhaust gases such as nitrous oxide, oxygen, and biological
substances.
Introduction
[0003] Numerous devices are known for collecting and/or reclaiming
anaesthetic agents such as halogenated drugs or nitrous oxide.
[0004] For example U.S. Patent Number 3,592,191 (Jackson) discloses
a method and apparatus for recovering exhausted anaesthetic agents.
Recovery is effected by collecting the exhausted gas and removing the water
vapor either by condensation or with a hygroscopic material. The anesthetic
agent is then extracted from the dried gas by a cryogenic process in which the
vapors in the anesthetic agent are condensed. to a liquid phase or by an
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absorbent material, which is processed later to remove the agent. When
employing the condensing process, the anesthetic condensate is collected
and may be readmitted directly into the anesthetic system.
[0005] U.S. Patent Number 7,235,222 (Hotta et al.) discloses a process
and an apparatus for treating a waste anesthetic gas containing a volatile
anesthetic and nitrous oxide discharged from an operating room by
introducing the gas into an adsorbing cylinder filled with an adsorbent, where
the volatile anesthetic contained in the waste anesthetic gas is adsorbed and
thereby removed, and successively introducing the gas into a catalyst layer
filled with a nitrous oxide decomposition catalyst, where nitrous oxide is
decomposed into nitrogen and oxygen.
[0006] U.S. Patent Application Publication Number 2005/0155380
(Rock) discloses devices for the recovery of volatile, organic anesthetic
agents from waste anesthesia gas. The device recovers the anesthetic agents
by selectively condensing the agents in a cooling chamber and storing the
condensed agents in a pressurized storage chamber.
[0007] U.S. Patent Application Publication Number 2006/0254586
(Berry et al.) discloses a method and system for removal of nitrous oxide and
volatile halocarbon gas components from waste anesthetic gases using a low-
flow scavenging or reclamation system that preferably includes an intelligent
waste anesthetic gas collection unit fluidly coupled between each individual
anesthetic machine and the waste gas evacuation manifold. Through a
system including a collection chamber, a pressure detector, and an exhaust
valve which is actuated based on the detected pressure in the collection
chamber, the waste anesthetic gas collection unit allows flow to the waste
suction manifold only in the presence of waste gas and interrupts all flow
into
the suction manifold when no waste gas is present.
[0008] U.S. Patent Application Publication Number 2006/0254589
(Berry et al.) discloses a method and apparatus for recovering and separating
anesthetic gas components from waste anesthetic gases to be purged from a
healthcare facility. Prior to a condensation step, a compressor is used to
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increase the waste anesthetic gas pressure in order to facilitate condensation
of anesthetic gas components at higher temperatures and in greater amounts
than through condensation at lower pressures. Condensing the anesthetic gas
components from the compressed waste anesthetic gas stream is then
achieved using conventional condensation systems, which remove anesthetic
gases as either liquid condensates or solid frosts. Some embodiments may be
used with existing high-flow scavenging or reclamation systems but are more
preferably used with low flow scavenging or reclamation systems, which
employ intelligent waste anesthetic gas collection units to minimize the
ingress of atmospheric gas when no waste anesthetic gas is to be purged
from the healthcare facility.
[0009] In spite of these known devices, a need for apparatus, systems
and methods of collecting and/or reclaiming anaesthetic agents such as
halogenated drugs or nitrous oxide has been recognized.
Brief Description of the Drawings
10010] The drawings included herewith are for illustrating various
examples of methods and apparatus of the present specification and are not
intended to limit the scope of what is taught in any way. In the drawings:
[0011] Figure 1 is a schematic representation of a collection system for
collecting anaesthetic agents according to one embodiment;
[0012] Figure 2 is a schematic representation of a monitoring system
for use with the collection system of Figure 1;
[0013] Figure 2A is a flow chart illustrating a method for collection of
anaesthetic agents according to another embodiment;
[0014] Figure 3 is a schematic representation of an operating room and
a conservation valve of the collection system of Figure 1;
[0015] Figure 4 is a schematic representation of the conservation valve
of Figure 3;
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[0016] Figure 5 is a schematic representation of a conservation valve
connected to an anaesthetic machine according to another embodiment;
[0017] Figure 6 is a schematic representation of a first subsystem of a
collection system for collecting anaesthetic agents;
[0018] Figure 7 is a schematic representation of another subsystem for
use with the first subsystem of Figure 6, and which is operable to remove
nitrous oxide from exhaust gases using a reaction chamber;
[0019] Figure 8 is a schematic representation of another subsystem for
use with the first subsystem of Figure 6, and which is operable to remove
nitrous oxide from exhaust gases using a reaction chamber;
[0020] Figure 9 is a schematic representation of another subsystem for
use with the first subsystem of Figure 6, and which is operable to remove and
collect nitrous oxide;
[0021] Figure 10 a schematic representation of another subsystem for
use with the first subsystem of Figure 6, and which is operable to remove
nitrous oxide and oxygen from exhaust gases;
[0022] Figure 11 is a schematic representation of a first subsystem of a
yet another collection system for collecting anaesthetic agents, and which is
operable to remove biological substances;
[0023] Figure 12 a schematic representation of another subsystem for
use with the first subsystem of Figure 11, and which is operable to disinfect
exhaust gases prior to collecting the anaesthetic agents;
[0024] Figure 13 is a schematic representation of a first subsystem of a
yet another collection system for collecting anaesthetic agents; and
[0025] Figure 14 a schematic representation of another subsystem for
use with the first subsystem of Figure 13, and which is operable to disinfect
exhaust gases prior to collecting the anaesthetic agents.
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Detailed Description
[0026] Referring to Figure 1, illustrated therein is a collection system 10
for collecting or reclaiming anesthetic agents such as halogenated drugs or
nitrous oxide from one or more sources of exhaust gas according to some
embodiments. The collection system 10 may be installed in a healthcare
facility such as a hospital and may be centrally located such that it is in
fluid
communication with one or more sources of exhaust gas, such as one or
more operating rooms 12, 14, and 16.
[0027] Furthermore, the collection system 10 may be remotely located
relative to the operating rooms 12, 14, 16 and other sources of exhaust gas.
For example, the collection system 10 may be located within the hospital at a
location that is both central and remote relative to the individual operating
rooms 12, 14, 16 while remaining in fluid communication with the operating
rooms 12, 14, 16, (e.g. via piping, ducting or other mediums for transporting
liquids or gases, collectively referred to as "piping" herein).
[0028] The operating rooms 12, 14, 16 may be the source of one or
more exhaust gases. For example, each operating room 12, 14, 16 may have
an anaesthetic machine 20 that can be connected to one or more patients 18
for administering one or more anaesthetic agents (such as halogenated
drugs, nitrous oxide, etc.) during or in association with a medical procedure.
[0029] In some cases, the anaesthetic machine 20 may also collect
exhaust gases from the patient 18 and direct those exhaust gases to the
collection system 10, for example, through an exhaust port 24 in the operating
room. In some embodiments, a conservation valve 22 may be located
between the anaesthetic machine 20 and the exhaust port 24 as will be
described below.
[0030] In some embodiments, the exhaust gases may come from other
sources, such as an outpatient clinic, a surgery clinic, a doctor's office, an
oral
surgery clinic, a veterinary clinic, or other types of healthcare facilities.
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[0031] As shown, an Anaesthetic Gas Scavenging System 30
("AGSS"), also known as a Waste Anaesthetic Gas Disposal ("WAGD"), may
be connected to the operating rooms 12, 14, 16 and the collection system 10.
As shown, the AGSS 30 may be located between the operating rooms 12, 14,
16 and the collection system 10.
[0032] Generally, the AGSS 30 draws exhaust gases from the
operating rooms 12, 14, 16 or another source, and directs these exhaust
gases to the collection system 10. For example, the AGSS 30 may include a
power source such as a vacuum pump, blower, or fan connected to the
exhaust ports 24 of the operating rooms 12, 14, and 16 through piping. In
some instances, the power source may be connected to an inlet port 32 of the
collection system 10 through piping.
[0033] In some embodiments, the AGSS 30 may include two or more
power sources connected in parallel. Having an additional power source may
provide a back-up in case one power source stops operating (e.g. breaks
down or needs maintenance), which may improve system redundancy.
Additional power sources may also increase the suction, for example, when
the AGSS 30 is connected to larger systems (e.g. a greater number of
operating rooms). Furthermore, in some embodiments there may be more
than one AGSS 30, which may be connected in parallel, for example, to
provide redundancy.
[0034] Generally, the collection system 10 includes one or more
collectors 42 for collecting and removing anesthetic agents from the exhaust
gas. The collection system 10 may also include a dryer 40 for removing
moisture from the exhaust gas, and may include a dryer regeneration module
60 operatively coupled to the dryer 40 as will be described below.
[0035] The collection system 10 may also include a controller 80 for
controlling various subcomponents of the collection system 10 such as the
collectors 42, the dryer 40 and the dryer regeneration module 60 as will be
described below.
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[0036] Under normal operating conditions, exhaust gases entering the
collection system 10 typically pass through the dryer 40 first, and then
through
the collector 42. Accordingly, the dryer 40 and the collector 42 may be in
fluid
communication with each other.
[0037] After flowing through the dryer 40 and the collector 42, the
exhaust gas may exit the collection system 10 at an outlet port 44, which may
be coupled to an exhaust 46 that vents to atmosphere outside of a medical
facility.
[0038] As shown, the dryer 40 is in fluid communication with the inlet
port 32 and receives exhaust gas from the AGSS 30. Often, the exhaust gas
collected from the operating rooms 12, 14, and 16 may include moisture
entrained in the gas flow, which may adversely affect the amount of
anesthetic agent collected by the collectors 42. For example, moisture may be
exhaled by the patients 18 in the operating rooms 12, 14, 16 during medical
procedures.
[0039] The dryer 40 helps to remove this moisture from the exhaust
gas. For example, the dryer 40 may include desiccant material such as
activated alumina, or may use other methods of drying air, such as
condensation or membrane dryers, as will be described below.
[0040] The dryer 40 may be any suitable shape and size. For example,
the dryer 40 may be a tower having an inlet at the bottom of the tower and an
outlet at the top of the tower. In some cases, the size and shape of the tower
may be determined according to the amount of moisture to be removed.
[0041] In one example, the dryer 40 may include approximately 2.5
kilograms of alumina desiccant for each operating room (e.g. operating rooms
12, 14, 16), which may allow the dryer 40 to continuously dehumidify exhaust
gases from a typical patient for approximately eight hours. For example, in
the
illustrated embodiment, there are three operating rooms 12, 14, 16, and the
dryer 40 may include at least 7.5 kilograms of alumina desiccant.
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[0042] In some embodiments, more activated alumina may be provided
in the dryer 40 so as to provide a buffer. For example, in the illustrated
embodiment, approximately 10 kilograms of activated alumina may be
provided in the dryer 40. The dryer 40 may also include more desiccant so as
to provide a longer operating time (e.g. sixteen hours of continuous
operation).
[0043] After flowing through the dryer 40, the dryer 40 outputs a
dehumidified exhaust gas, which is then received by one or more collectors
42. In the illustrated embodiment, the collectors 42 adsorb anaesthetic agents
from the exhaust gas. For example, the collectors 42 may include hollow
vessels containing adsorbent material made from hydrophobic molecular
sieves as generally described in U.S. Patent Number 5,231,980 (Filipovic).
The hydrophobic molecular sieves may be of the high silica zeolite type.
According to Filipovic, such adsorbent materials have pore diameters large
enough to permit molecules of halogenated drugs to pass therethrough and
be selectively adsorbed in large internal cavities of the crystal framework,
whereby halogenated drugs may be removed.
[0044] While the embodiment described above refers to a hydrophobic
molecular sieve for collecting and reclaiming halogenated drugs, the collector
42 may collect anaesthetic agents using different materials or methods. For
example, the collector 42 may utilize other adsorbent materials such as other
types of molecular sieves or activated charcoal to collect and reclaim
halogenated drugs. In some cases the collector 42 could use a cryogenic
collector.
[0045] In normal operation, the exhaust gas passes through the
collector 42 even when the collector is saturated or cannot remove
anaesthetic agents from the exhaust gas flow. However, once the collector is
full, the flow of exhaust gases may be diverted from the collector 42 that is
full, and the anaesthetic agents may be recovered from that particular
collector 42 for later reuse.
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[0046] For example, when using the hydrophobic molecular sieve
described by Filipovic, the exhaust gases may pass through a bed of
adsorbent material until the material in the sieve is saturated to the extent
that
breakthrough of the hydrocarbons is determined (e.g. halogenated
hydrocarbons are detected at the outlet of the collector). Next, the adsorbent
material with the adsorbed phase of halogenated hydrocarbons may be
removed from the system and regenerated by exposing the saturated material
to an inert purging gas stream under conditions which desorb the halogenated
hydrocarbons from the adsorbent material into the purging gas stream. The
halogenated hydrocarbons may then be removed from the purging gas stream
and purified to a desired level of purity for reuse of the recovered
halogenated
hydrocarbons.
[0047] In some embodiments, a third party may remove the anaesthetic
agents (e.g. halogenated hydrocarbons) from the collector 42.
[0048] In some embodiment, after recovering the anaesthetic agents
from the collector 42, the collector 42 may be reinstalled in the system 10.
Accordingly, the collector 42 may be reused multiple times.
[0049] When recovering anaesthetic agents from the collector 42 it may
be desirable to keep the system 10 operational so as to provide continuous
collection of anaesthetic agents. Accordingly, the system 10 may include a
plurality of collectors 42 (e.g. collector bank "A" and collector bank "B")
connected together in parallel so that at least one collector 42 remains
operational while one or more other collectors 42 are being processed to
remove the captured anaesthetic agents, for example.
[0050] When there is a plurality of collectors 42 connected in parallel,
the inlet of each collector 42 may include a valve 50 for selectively opening
and closing the flow of exhaust gases into the respective collector 42 from
the
dryer 40. This valve 50 may be closed when removing the respective collector
42 from the system 10, for example, when recovering anaesthetic agents from
each respective collector 42. At the same time, other collectors 42 may have
open valves 50 such that dehumidified exhaust gases are permitted to flow
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into those other collectors. Accordingly, the collection system 10 may remain
operational while some of the collectors 42 are being processed.
[0051] The collection system 10 may also include a sensor 52 for
measuring an amount of anaesthetic agent collected and for detecting when
one of the collectors 42 is full, for example, so that anaesthetic agents can
be
reclaimed, for example, by removing/exchanging the collector 42 from the
system 10. In some embodiments, the sensor 52 may be a weight scale that
measures the weight of the collector 42 (e.g. when the collector 42 is a
hollow
vessel). Upon reaching a particular weight, the collector 42 may be
removed/exchanged from the system 10 so that the anaesthetic agent may be
recovered from the collector 42.
[0052] In some embodiments, the collector 42 may have multiple
stages for removing anaesthetic agents from the exhaust gas. For example,
each collector 42 may include a first stage 54 and a second stage 56. The
stages 54, 56 may use one or more different methods or devices for collecting
or reclaiming anaesthetic agents from the exhaust gas. For example, the first
stage 54 may include a first type of adsorbent material such as a molecular
sieve that tends to adsorb a first type of anaesthetic agent (e.g. Sevoflurane
or Desflurane, or both) for later reuse. The second stage 56 may include a
second adsorbent material such as a molecular sieve that tends to adsorb a
second type of anaesthetic agent (e.g. a halogenated drug such as lsoflurane)
for later reuse.
[0053] Accordingly, a multi-stage collector 42 may allow the collection
system 10 to collect two or more types of anaesthetic agents for later reuse.
This may be useful when implementing a centralized collection system 10 that
recovers anaesthetic agents from multiple sources of exhaust gas that may
contain multiple different anaesthetic agents.
[0054] In some embodiments, each of the first and second stages 54,
56 may collect more than one type of anaesthetic agent. For example, the first
stage 54 may collect a plurality of anaesthetic agents such as all halogenated
drugs. However, even if the first stage collects a plurality of anaesthetic
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agents, the first stage 54 may preferentially collect one or more anaesthetic
agents in comparison to other anaesthetic agents. For example, the first stage
54 may collect all halogenated drugs, but may also collect Sevoflurane and
Desflurane to a greater extent than Isoflurane.
[0055] While the illustrated embodiment shows two stages 54, 56, the
collector 42 may include any number of stages. For example, there may be
additional stages to reclaim other anaesthetic agents for later reuse,
including
but not limited to other halogenated drugs or nitrous oxide. In some
embodiments, the collector 42 may include a single stage.
[0056] In some embodiments, the multiple stages of the collector 42
may serve purposes other than reclaiming multiple types of anaesthetic
agents for later reuse. For example, the second stage 56 may include a
second adsorbent material, such as activated charcoal, that functions as a
fail-safe that may help prevent at least some anaesthetic agents from exiting
the collection system 10, and which could otherwise lead to pollution.
[0057] For example, activated charcoal may adsorb one or more
anaesthetic agents, but it may be impractical to recover those adsorbed
anaesthetic agents from the activated charcoal. In this sense, the activated
charcoal may be disposable and may merely sequester the anaesthetic
agents, as opposed to allowing them to be reclaimed for later reuse.
Nonetheless, providing a second stage 56 with activated charcoal or similar
materials may help reduce pollution and generally provide for cleaner exhaust
gases.
[0058] In some embodiments, one or more collectors 42 or stages
thereof may act as a sequestration device that collects anaesthetic agents for
disposal, as opposed to later reuse. For example, the collector 42 may be a
vessel containing activated charcoal and it may be impractical to recover the
anaesthetic agents from the activated charcoal for reuse.
[0059] In some embodiments, the collection system 10 may not include
a dryer 40. For example, this may be possible when the system 10 includes a
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collector 42 that functions relatively independent of moisture content in the
exhaust gas flow, such as a molecular sieve (which could be hydrophobic).
However, providing a dryer 40 may improve the efficiency of a hydrophobic
molecular sieve, for example, because it has been determined that
hydrophobic molecule sieves might tend to adsorb some water in addition to
anaesthetic agents.
[0060] When the system 10 includes a dryer 40, it may become
saturated or otherwise unable to remove moisture from the exhaust gas.
Accordingly, the collection system 10 may include a dryer regeneration
module 60 for removing or purging collected moisture from the dryer 40. For
example, when the dryer 40 includes alumina desiccant, the regeneration
module 60 may be operable to blow air through the desiccant in the dryer 40
under proper conditions that purge moisture from the dryer 40 and recharge
the desiccant.
[0061] For example, the regeneration module 60 may include an inlet
filter 62, a blower 64, a check valve 66 and a heater 68. In use, the blower
64
draws a purging gas such as air through the inlet filter to remove impurities
that may otherwise damage the desiccant in the dryer 40. The filtered air
exits
the blower 64 and passes through a one-way check-valve 66 and then into
the heater 68 where the air is heated to a temperature sufficient to remove
moisture from the desiccant in the dryer 40. The air then proceeds through the
dryer 40 and may then vent to atmosphere through the exhaust 46.
[0062] As described above, the heater 68 heats the air to a
temperature sufficient to purge moisture from the desiccant. For example, the
temperature may range from approximately 60 C to 300 C. In some
embodiments, the regeneration module 60 may provide air at approximately
200 C and 20 cubic feet per minute for approximately six hours, which may be
sufficient to remove moisture from approximately 7.5 kilograms of activated
alumina desiccant.
[0063] In some cases, the dryer 40 is generally allowed to cool after the
desiccant is purged with hot air. The cooling time may be approximately two
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hours. After this time, the dryer 40 may be used once again to remove
moisture.
[0064] As described above, the dryer 40 may be configured to operate
continuously for between about 8-16 hours after being regenerated by the
dryer regeneration module 60, which may be sufficient to operate the
collection system 10 for an entire day. At the end of the day, the dryer 40
may
be purged of collected moisture using the process described above. This
process may take approximately 8 hours, which means in some cases the
system 10 can be purged at night while the system 10 is not in use. Once
purged, the system 10 can resume normal operations the following day.
[0065] In some embodiments, the dryer 40 may be configured to
operate for longer periods of time. In some embodiments, there may be two or
more dryers 40 fluidly coupled in parallel so that the system 10 can operate
continuously. In this sense, the dryers 40 may have a similar configuration to
the collectors 42 described above.
[0066] When purging moisture from the dryer 40 using the regeneration
module 60, the air may proceed through the dryer 40 in reverse (e.g. from the
outlet of the dryer to the inlet of the dryer). For example, the regeneration
module 60 may be connected to an outlet port located near the top of the
dryer 40, and an inlet port on the bottom of the dryer 40 may be connected to
the exhaust 46. This configuration may help purge moisture from the dryer 40
because with high down flow purge air the desiccant material may be
compacted and may increase the surface area contact, which may tend to
avoid channelling, fluidization and dust release from the desiccant bed.
[0067] In some other embodiments, the regeneration module 60 may
blow air into the dryer 40 in the normal flow direction.
[0068] While the illustrated embodiment shows the dryer 40 having two
inlet ports and two outlet ports, there may be one inlet port and one outlet
port
that are connected to respective components, for example, using T-
connectors or manifolds.
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[0069] In some embodiments, the system 10 may include control
valves 50, 70, and 72 that control the direction of airflow through the dryer
40
and other elements of the system 10. These valves 50, 70 and 72 may inhibit
air from flowing into the AGSS 30 or into the collectors 42 when the
regeneration module 60 blows air through the dryer 40. For example, when
regenerating the dryer 40, valves 50 and 72 may be closed, and valve 70 may
be open. The outlet of the valve 70 may be connected to the outlet port 44 of
the system 10 for venting air to atmosphere. Once the dryer 40 has been
purged and regenerated, the valve 70 may be closed and the other valves 50
and 72 may be opened to resume normal operations and continue collecting
or reclaiming anaesthetic agents.
[0070] In some embodiments the valves 50, 70, 72 may be manually
controlled.
[0071] In some embodiments, the valves 50, 70, 72 may operate
automatically. For example, the valve 72 may be a check valve. In another
example, the valves may be controlled by a controller 80 or monitoring system
90 as will be described below.
[0072] In some embodiments, the controller 80 (such as a control
panel) may be configured to automate the system 10. For example, the
controller 80 may monitor the status of the dryer 40 and/or the status of the
collectors 42 (e.g. via the sensor 52) to determine if they are full and need
to
be replaced or regenerated. The controller 80 may also operate the dryer
regeneration module 60 and the valves 50, 70 and 72 depending on the
capacity of the dryer 40. For example, there may be a sensor (e.g. similar to
or the same as sensor 52) for measuring the amount of moisture collected by
the dryer 40 and the controller 80 may be in communication with that sensor,
for example, to operate the dryer regeneration module 60 when the dryer 40
is full or almost full.
[0073] In some embodiments, the system 10 may be manually
operated. For example, the dryer regeneration module 60 and the valves 50,
70, 72 may be manually operated. The system 10 may also have both
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automated and manual operation modes, for example, to provide system
redundancy and safety.
[0074] In some embodiments, the system 10 may include a bypass or
failsafe so that exhaust gases may bypass the dryer 40 and/or collectors 42
and/or other components of the system 10. It may be desirable to use a
bypass when conducting maintenance or servicing of the system 10.
[0075] For example, the collection system 10 may include a bypass
valve 84 connected between the inlet port 32 and the outlet port 44. In some
embodiments, the bypass valve 84 may be operated automatically. In this
sense, the bypass valve 84 may be a fail-safe valve that enhances safety,
such as a normally open, energized closed, spring return ball valve, piston
valve, blow-off valve or a burst disc. In other embodiments, the bypass valve
84 may be operated manually.
[0076] The system may also include control valves 86, 88 that isolate
the components of the system 10, for example, when the bypass valve 84 is
in use. For example, valves 86, 88 may be closed when'the bypass valve 84
is open. The opening and closing of the valves 84, 86, 88 may be automated
and may occur at the same time or at different times.
[0077] As described above, the collection system 10 may be located
centrally and remotely from one or more sources of exhaust gas (e.g. the
operating rooms 12, 14 and 16). Having a centrally located system may
decrease the overall cost of the collecting or reclaiming anaesthetic agents
in
comparison to conventional systems that are located at or near the source of
the exhaust gas. As such, the initial capital costs of providing a large
central
collection system may be less than the accumulative cost of several smaller
localized systems.
[0078] Furthermore, operational costs of a centralized system may be
lower in comparison to a local system because the centralized system 10 may
be able to more easily implement a monitoring system that controls the
collection and reclamation of anaesthetic agents from each source of exhaust
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gas. Tracking the collection of multiple sources of exhaust gas may help
determine when servicing or maintenance is necessary, which may result in
increased uptimes. For example, the monitoring system may track the
capacity of the dryer 40 and/or collectors 42 so that they may be replaced or
regenerated once they are saturated or otherwise full. Monitoring one central
system in this way may be less expensive than monitoring several individual
localized systems.
[0079] Referring now to Figure 2, a sample monitoring system 90 will
now be described in greater detail. The monitoring system 90 generally
includes a processor 92 that is in electronic communication (e.g. via a wired
or wireless network) with the collection system 10 and the various
subcomponents thereof such as the dryer 40, the collectors 42, the valves 50,
70, 72, the sensors 52, and the regeneration module 60.
[0080] The processor 92 may be a computer, microprocessor or
another other suitable device for monitoring the collection system 10. In some
embodiments, the processor 92 may be implemented in electronics that are
part of the controller 80 within the system 10. In some embodiments, the
processor 92 may be located separately and remotely from the collection
system 10 altogether, and may be in communication with a plurality of
collection systems 10 as will be described in greater detail below. In these
cases, the processor 92 may be in communication with the controller 80 of
each of the plurality of collection systems 10.
[0081] Generally, the processor 92 may communicate with the sensors
52 to determine when the collectors 42 are full. When the collectors 42 are
full
(or when the sensor 52 measures a particular amount of anaesthetic agent
collected), the monitoring system 90 may initiate reclamation of the
anaesthetic agent, for example, by initiating a process to purge or exchange
the collector 42 that is full. For example, when using some collectors 42 with
hydrophobic molecular sieves, it may be necessary to remove and/or
exchange the collector 42 (e.g. a hollow vessel of hydrophobic material) from
the system 10 to recover the anaesthetic agents captured therein. When one
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collector 42 is being removed/exchanged, the processor 92 may divert the
flow of exhaust gases to one or more other collectors 42 that are still
operational, for example, by opening or closing the valves 50.
[0082] Furthermore, when one or more hollow vessels are full, the
monitoring system 90 may alert a collection agent 94 in order to request pick
up and exchange the full vessels with empty ones. For example, the
processor 92 may communicate with a third party collection agent 94 via a
communications network 96 such as the Internet. After receiving the alert, the
third party collection agent 94 may recover anaesthetic agents from the full
vessels and may sell the anaesthetic agents back to pharmaceutical
companies 99, directly to the medical facility, and so on. In some
embodiments, the collection agent 94 may be an affiliate of the entity that
provides the monitoring system 10 or monitoring services.
[0083] The monitoring system 90 may also be adapted to keep track of
the overall amount of anaesthetic agents recovered for tax saving or other
accounting purposes. For example, the amount of anaesthetic agents
recovered by a particular legal entity may allow that entity to claim tax
credits
such as carbon credits. Being able to track these tax credits may be
particularly beneficial to drug companies and hospitals and may provide
financial benefits.
[0084] To keep track of this tax saving or other accounting information,
the monitoring system 90 may include a data storage medium 98 such as a
hard drive or database connected to the processor 92. The processor 92 may
keep track of the overall amount of anaesthetic agents recovered and the
storage medium 98 may store the tax savings information for later use.
[0085] The monitoring system 90 may also track the status of multiple
collection systems 10. For example, there may be a plurality of medical
facilities in a particular geographic area or region, with each medical
facility
having a centralized collection system 10. The processor 92 may be in
communication with each of these collection systems 10 directly or through
the communications network 96 so as to track overall collection and
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reclamation of anaesthetic agents for that geographic region. This information
may be stored on the storage medium 98 for later use (e.g. for calculating tax
credits).
[0086] In some embodiments, the monitoring system 90 may be
adapted to provide supply chain management for a particular geographic
region, for example, by keeping track of the demand of each healthcare
facility and the amount of anaesthetic agents each healthcare facility
recovers. The monitoring system 90 may then allocate the recovered
anaesthetic agents to the facilities based on demand, and may order fresh
anaesthetic agents (e.g. from a pharmaceutical supply company) based on
demand. Accordingly, in such embodiments the processor 90 may be in
communication with the pharmaceutical company 99, for example, through
the communications network 96.
[0087] Referring now to Figure 2A, illustrated therein is a method 100
for monitoring collection of anaesthetic agents.
[0088] Step 101 includes communicating with at least one collection
system. For example, the processor 92 may communicate with the one or
more collections systems over a wired or wireless communication network.
The collection system(s) may be similar to the collection system 10 described
above. Each collection system generally includes at least one collector (e.g.
the collector 42) for collecting an anaesthetic agent from an exhaust gas that
includes the anaesthetic agent. In some embodiments, step 101 may include
communicating with a plurality of collection systems, which may be located
remotely.
[0089] Step 102 includes measuring an amount of anaesthetic agent
collected by each collector. For example, the sensors 52 may be used to
measure the amount of anaesthetic agent collected by the collectors 42.
[0090] Step 103 includes initiating reclamation of the anaesthetic agent
from a collector after measuring a particular amount of anaesthetic agent
collected by the respective collector. For example, reclamation may be
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initiated when the sensor 52 detects that the respective collector 42 is full,
or
almost full.
[0091] Step 104 includes tracking an overall amount of anaesthetic
agent collected. For example, the storage medium 98 may be used to track
the overall amount of anaesthetic agent collected. Furthermore, the storage
medium 98 may track the overall amount of anaesthetic agent collected by a
plurality of collection systems.
[0092] Step 105 includes calculating tax credits corresponding to the
overall amount of anaesthetic agent collected. For example, the processor 92
may calculate the tax credits.
[0093] Referring again to Figure 1, as shown the collection system 10
is located downstream from the AGSS 30. Furthermore, in the illustrated
embodiment, the AGSS 30 is an active system, which tends to provide a
positive pressure downstream of the AGSS 30 (e.g. approximately 3 psi) and
provides suction of the exhaust gas under negative pressure upstream of the
AGSS 30 (e.g. approximately 12-20 inches-Hg). Connecting the collection
system 10 to the exhaust side of the AGSS 30 provides an opportunity to
collect anaesthetic agents under positive pressure, which may increase the
efficiency of the collectors 42 because the adsorption of anaesthetic agents
may be reduced under high negative pressures (e.g. 12-20 inches-Hg).
[0094] In some embodiments, the AGSS 30 may include a vacuum
pump and the collection system 10 may be connected to the outlet of the
vacuum pump. Accordingly, the collection system 10 might receive exhaust
gases having a positive pressure, and may thereby collect aesthetic agents
under positive pressure, which may increase the efficiency of the collection
system 10, particularly when utilizing adsorption collectors 42 that include
molecular sieves.
[0095] In some other embodiments, the collection system 10 may be
located upstream of the AGSS 30. For example, the collection system 10 may
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be located upstream of a passive AGSS, which may provide a low negative
pressure, such as approximately 0.1 inches-WC (water column).
[0096] Referring now to Figures 1, 3 and 4, the conservation valve 22
will now be described in greater detail.
[0097] As shown in Figures 1 and 3, the conservation valve 22 is
located between the AGSS 30 and the anaesthetic machine 20. The
conservation valve 22 is operable to selectively open and close the fluid
passage between the anaesthetic machine 20 and the AGSS 30, for example,
depending on whether or not the anaesthetic machine 20 is actually in use.
This may increase the efficiency of the collection system 10 and/or AGSS 30
as will be described below.
[0098] Referring now to Figure 4, as shown the conservation valve 22
includes a valve body 108 having an inlet port 112, an outlet port 114, and a
fluid passageway 110 therebetween. The conservation valve 22 also includes
an actuator 116 for selectively opening and closing the fluid passageway 110
between the inlet 112 and outlet 114.
[0099] Generally, the inlet port 112 is connected to a source of exhaust
gas (e.g. via the anaesthetic machine 20) so as to allow the exhaust gas to
flow through the fluid passageway 110, and the outlet port 114 is connected to
the collection system 10 (e.g. via the AGSS 30). The inlet 112 and outlet 114
may have connectors for connecting the conservation valve 22 to piping,
tubes, or other mediums for transporting liquids or gases. For example, the
inlet 112 may have a 1/4-inch NPT female thread. Similarly, the outlet 114
may have a 1/4-inch NPT female thread.
(00100] The actuator 116 is generally located within the fluid
passageway 110 and may be any device for controlling fluid flow, such as an
electronically controlled solenoid valve. In some embodiments, the actuator
116 may be a solenoid valve, a part-turn actuator such as a ball valve, or a
linear actuator such as a diaphragm valve. In some embodiments, the
actuator 116 may be operated by electronics, pneumatics or hydraulics.
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[00101] The actuator 116 may open and close the fluid passageway 110
based on the presence or absence of exhaust gases coming from the source
(e.g. the anaesthetic machine 20 or the patient 18). As such, the conservation
valve 22 may include a sensor 120 that detects the presence or absence of
exhaust gases so as to open and close the fluid passageway. The sensor 120
may be connected to the source of exhaust gases upstream of the valve body
108. For example, in Figure 1, the sensor 120 is connected between the
patient 18 and the anaesthetic machine 20.
[00102] In some embodiments, the sensor 120 may detect the presence
or absence of one or more compounds in the exhaust gases that indicate
whether or not there is a flow. For example, the sensor 120 may detect a
compound such as oxygen. In particular, the percentage of oxygen in the
exhaust flow may indicate whether or not a patient is breathing through the
anaesthetic machine 20, and as such, may indicate whether or not the
anaesthetic agent is present in the exhaust gas.
[00103] In use, the sensor 120 may measure an ambient oxygen content
corresponding to an ambient condition, for example, when the anaesthetic
machine 20 is not in use. The ambient oxygen content may be approximately
21 %, which is typically the natural oxygen content in air. When the sensor
120
detects a change in oxygen content, for example, a measured oxygen content
above the ambient oxygen (e.g. because the anaesthetic machine is
supplying enriched oxygen) or below the ambient oxygen (e.g. the patient is
consuming oxygen), this may indicate the anaesthetic machine is in use, and
the valve 22 may be opened.
[00104] In some embodiments, the sensor 120 may continue monitoring
the oxygen content to determine if ambient conditions have re-established
such that measured oxygen content returns to approximately the ambient
oxygen content, which may indicate the anaesthetic machine 20 is no longer
in use. If this occurs, the valve 22 may be closed.
[00105] In some embodiments, the valve 22 may open and close based
on a measured oxygen content falling within a range around the ambient
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oxygen content. For example, the range may account for error tolerances in
the sensor 120, such as an error of plus or minus approximately 10%. In
some embodiments, the range may be approximately 19% to 23% oxygen
content when the ambient oxygen content is 21 % and the valve 22 may open
when the oxygen content falls outside of the 19% to 23% range. The range
may also be selected to account for the amount of oxygen a patient
consumes, which may be approximately 5%.
[00106] In some embodiments, the sensor 120 may measure the oxygen
content after a period of time or over a particular time interval. For
example,
after opening the valve based on a change in the measured oxygen content,
the sensor 120 may measure the oxygen content every sixty seconds, or may
measure and calculate the average oxygen content over sixty seconds. This
may help account for fluctuations in the oxygen content, which may be
associated with error tolerances for the sensor 120, changes in the patient's
breathing, or other factors. In some embodiments, the time period or time
interval may be longer or shorter than sixty seconds. For example, in some
instances the time period or time interval may be between approximately ten
seconds and five minutes.
[00107] After the valve 22 opens, the valve 22 may remain open for a
particular waiting period even if the measured oxygen content returns to a
level corresponding to the ambient oxygen content or an appropriate range.
For example, in some instances the waiting period may be any time between
approximately one minute and approximately one hour. In some particular
embodiments, the waiting period may be approximately one minute.
[00108] Providing a waiting period may help reduce the possibility of
closing the valve prematurely, for example, when the sensor 120 makes an
erroneous measurement.
[00109] In some embodiments, the sensor 120 may detect other
compounds, such as anaesthetic agents or carbon dioxide. In some
embodiments, the sensor 120 may detect a flow or change in pressure as a
trigger for opening and closing the valve.
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[00110] Referring to Figure 4, the conservation valve 22 may also
include a processor 130 for controlling the actuator 116 based on conditions
detected by the sensor 120. The conservation valve 22 may also include a
power supply 132 for providing power to the processor 130, the sensor 120
and the actuator 116.
[00111] As shown, in some embodiments, one or more subcomponents
of the conservation valve 22 may be located inside a housing 140, which may
be made of metal, plastic, or another suitable material. For example, the
valve
body 108, the actuator 116, and the processor 130 may be located inside the
housing 140, while the sensor 120 and the power supply 132 may be located
outside the housing 140. In some embodiments, the sensor 120 and the
power supply 132 may also be located inside the housing 140.
[00112] The conservation valve 22 may tend to increase efficiency of the
AGSS 30. For example, if the AGSS 30 operates continuously, it may operate
even when the anaesthetic machine 20 is turned off and there are no
anaesthetic agents in the flow. This may waste power and reduce efficiency,
as the AGSS 30 will be processing gas even when no anaesthetic agents are
present.
[00113] In contrast, the conservation valve 22 may isolate the source of
exhaust gas from the AGSS 30 when the anaesthetic machine 20 is turned
off. This may increase the efficiency of the AGSS 30 because the power
source may not have to work as hard when one or more conservation valves
22 are closed.
[00114] In some embodiments, the conservation valves may also allow
the AGSS 30 to shut off when one or more (e.g. all) of the anaesthetic
machines 20 are turned off. This may further increase the efficiency of the
AGSS 30.
[00115] The conservation valve 22 may also increase the efficiency of
the collection system 10 by isolating the sources of exhaust gas from the
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collection system 10 when the anaesthetic machine 20 is turned off and there
are no anaesthetic agents in the exhaust gas flow.
[00116] More particularly, the conservation valve 22 may increase the
efficiency of the dryer. For example, when there are no anaesthetic agents in
the exhaust gas flow, the dryer 40 may unnecessarily remove moisture.
Closing the conservation valve 22 tends to isolate these inactive sources from
the dryer 40, which may increase the potential operation time for the dryer 40
and may reduce the need to purge and regenerate the dryer 40.
[00117] The conservation valve 22 may also increase the efficiency of
the collectors 42. For example, when room air (without anaesthetic agents)
flows through collectors 42 that use adsorbent material, the clean air may
displace captured anaesthetic agents and carry those anaesthetic agents to
the exhaust 46. This may have the undesired effect of purging the collector 42
of anaesthetic agents, which may reduce the collection efficiency of the
collectors 42. Closing the conservation valves 22 tends to reduce the amount
of room air that is processed by the collectors 42 and may prevent
unintentional purging.
[00118] Referring now to Figure 5, illustrated therein is a conservation
valve 200 connected to an anaesthetic machine 20 according to another
embodiment. The conservation valve 200 is similar in many respects to the
conservation valve 22, and where suitable, similar elements are given similar
reference numerals incremented by one hundred.
[00119] One difference is that the conservation valve 200 includes a flow
sensor 220 for measuring the flow of exhaust gas from the anaesthetic
machine 20. The flow sensor 220 may control the operation of the actuator
216 to selectively open and close the fluid passageway 210 based on the
presence or absence of fluid flow.
[00120] As shown, the flow sensor 220 is located upstream of the valve
body 208. For example, the flow sensor 220 may be connected to the inlet of
the anaesthetic machine 20 and may receive exhaust gases from a patient.
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The flow sensor 220 may measure the flow rate in terms of volume or mass of
the exhaust gas. If the flow rate drops below a certain threshold, the flow
sensor 220 may trigger the actuator 216 to close. If the flow rate exceeds a
certain threshold, the flow sensor 220 may trigger the actuator 216 to open.
[00121] The flow sensor 220 may also include a pressure sensor, which
may help indicate whether or not the anaesthetic machine 20 is in use when
the actuator 216 is in the closed position. If the pressure exceeds a certain
threshold, the flow sensor 220 may trigger the actuator 216 to open.
[00122] In some embodiments, the flow sensor 220 may communicate
with the actuator 216 via the processor 230. In other embodiments, the flow
sensor 220 may communicate directly with the actuator 216.
[00123] In some embodiments, the flow sensor 220 may cooperate with
another sensor to determine the presence or absence of exhaust gas flowing
from the source. For example, the processor 230 may determine if there is a
flow of exhaust gas based on both the flow rate from the flow sensor 220 and
the content of a particular compound in the flow as determined by the other
sensor (e.g. the sensor 120). This may be useful when there is ambient flow
through the anaesthetic machine 20 but anaesthetic agents are not being
delivered to the patient.
[00124] The conservation valve 220 may also include a switch 250 (e.g.
a flow switch or limit switch) connected to the valve body 208 within the
fluid
passageway 210 between the inlet 212 and the outlet 214, and downstream
of the actuator 216. A flow switch helps determine whether the actuator 216 is
open or closed based on the presence or absence of a flow after the actuator
216, and as such, the flow switch tends to confirm whether the valve 200 is
operational. In contrast, a limit switch helps determine whether the actuator
216 is open or closed based on the position of the actuator 216, and as such,
the limit switch tends to confirm whether the valve 200 is operational in a
different way compared to the flow switch.
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[00125] Turning now generally to Figures 6 to 10, in some embodiments
it may be desirable that at least some nitrous oxide gas be removed from the
exhaust gases before venting the exhaust gases to atmosphere. Nitrous oxide
is a greenhouse gas believed to account for a significant proportion of
atmospheric heating effects, as well as cause ozone depletion. Furthermore,
producing nitrous oxide can be expensive. Accordingly, it may be beneficial if
at least some nitrous oxide can be removed and/or collected (e.g. for reuse)
as opposed to being vented to atmosphere.
[00126] Turning now specifically to Figure 6, illustrated therein is a first
subsystem 300 of a system for collecting anaesthetic agents, and which is
configured to cooperate with one or more other subsystems (as described in
Figures 7 to 10) for removing at least some of the nitrous oxide prior to
venting to atmosphere.
[00127] As shown, the first subsystem 300 includes an AGSS 330
(which may be the same as or similar to the AGSS 30 as generally described
above). The AGSS 330 is in fluid communication (e.g. via piping 313) with one
or more sources of exhaust gases, such as one or more operating rooms 312
having one or more patients 318 therein. As shown the piping 313 allows
exhaust gases to pass from the operating rooms 312 to the AGSS 330,
including nitrous oxide (N20), anaesthetic agents such as halogenated drugs
(Hal. Drugs or HD), water or moisture (H20), and optionally in some cases air.
[00128] In turn, the AGSS 330 is in fluid communication with one or
more other subsystems. For example, as indicated by reference numeral "A",
in some embodiments the AGSS 330 may communicate with a second
subsystem 302 shown in Figure 7. Similarly, as indicated by reference
numeral "B", in some embodiments the AGSS 330 may communicate with a
third subsystem 304 shown in Figure 8. Furthermore, as indicated by
reference numeral "C", in some embodiments the AGSS 330 may
communicate with a fourth subsystem 306 shown in Figure 9. Finally, as
indicated by reference numeral "D", in some embodiments the AGSS 330 may
communicate with a fifth subsystem 308 shown in Figure 10.
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[00129] In some embodiments, the AGSS 330 may include one or more
filters 330a for filtering the incoming exhaust gases. For example, the
filters
330a could be ultra-low particulate air (ULPA) filters. In other embodiments,
the filters 330a could be high efficiency particulate air (HEPA) filters.
[00130] In some embodiments, a Med Vac may be used as the AGSS
330.
[00131] Turning now specifically to Figure 7, as shown therein the
second subsystem 302 is operable remove at least a portion of the nitrous
oxide from the exhaust gases before venting at least some of those gases to
atmosphere.
[00132] The second subsystem 302 includes a collection system 310,
which may be similar to or the same as the collection system 10 as generally
described above, and which is operable to receive gases from the AGSS 330.
For example, the collection system 310 may include components such as a
dryer 340 (which could be the same as or similar to the dryer 40 as described
above) for removing moisture from the incoming exhaust gases, and one or
more collectors 342 located downstream from the dryer 340 for collecting and
removing anaesthetic agents from the exhaust gas. In some embodiments,
the collectors 342 could be the same as or similar to the collectors 42 as
generally described above.
[00133] In this embodiment, the collector 342 is shown as an adsorbent
collector although other collectors could also be used.
[00134] In some embodiments, the collection system 310 may include
one or more filters 301a for filtering the incoming gases, such as a ULPA or
HEPA filter. As shown, the filters 301a may be provided upstream of the dyer
340 and collector 342.
[00135] As shown, moisture removed by the dryer 340 can be vented to
atmosphere via an exhaust 346 (coupled to the dryer 340 via a fluid conduit or
piping 341). Furthermore, in this embodiment, the anaesthetic agents
collected using the collectors 342 are sent for disposal (e.g. via a fluid
conduit
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or piping 343). For example, in some embodiments the anaesthetic agents
may be collected in large (e.g. 45-gallon) drums and then shipped to a
disposal facility.
[00136] As shown, in this embodiment, the gas products exhausted by
the collectors 342 are sent via piping 345 to one or more reaction chambers
347. Generally, each reaction chamber 347 is operable to decompose the
nitrous oxide (N20) into its component parts, namely nitrogen gas (N2) and
oxygen (02), according to the following relationship:
N20 4 N2 +'/2 02
[00137] For example, the reaction chamber 347 may operate at an
elevated temperature to heat the incoming nitrous oxide and encourage the
decomposition of the nitrous oxide into nitrogen gas and oxygen. In some
embodiments the reaction chamber 347 may be operated at temperatures of
around 200 degrees Celsius. In other embodiments, the reaction chamber
347 may be operated at higher or lower temperatures.
(00138] In some embodiments, one or more catalysts may be provided
to the reaction chamber 347 to facilitate driving the decomposition of the
nitrous oxide into nitrogen and oxygen. For example, the catalyst may include
precious metals (e.g. platinum, palladium, rhodium, etc.) or metal oxides
(e.g.
cupric oxide, chromium oxide, ferric oxide, etc.).
(00139] By breaking down the nitrous oxide into its component parts, at
least some of the nitrous oxide that would otherwise be vented to atmosphere
through the exhaust 346 can be converted into other (less damaging) gases.
As such, the gases sent via piping 349 from the reaction chamber 347 to the
exhaust 346 will tend to include reduced amounts of nitrous oxide (and in
some events, may be substantially or even completely stripped of nitrous
oxide).
(00140] Turning now specifically to Figure 8, the third subsystem 304 is
also operable to work with the first subsystem 300 for removing at least a
portion of the nitrous oxide from the exhaust gases. Generally, the third
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subsystem 304 is substantially similar to the second subsystem 302 as shown
in Figure 7, except that in this embodiment, the anaesthetic agents collected
using the one or more collectors 342 are sent for reclamation (e.g. via piping
343 to a reclamation plant) instead of for disposal. In some embodiments the
anaesthetic agents may be collected in large (e.g. 45-gallon) drums and then
shipped to a reclamation facility.
[00141] Turning now specifically to Figure 9, as shown therein the fourth
subsystem 306 is also operable to work with the first subsystem 300 for
removing at least a portion of the nitrous oxide from the exhaust gases. The
fourth subsystem 306 may include elements similar to the second subsystem
302 and third subsystem 304, including a collection system 310 having a
dryer 340 and one or more collectors 342.
[00142] However, in this embodiment the gases exiting the collectors via
piping 345 are sent to a compressor 351 or other similar component, and are
not sent to a reaction chamber 347.
[00143] The compressor 351 is operable to compress the gas mixture,
which may result in higher concentrations of nitrous oxide. The compressed
nitrous oxide gas is then sent via piping 353 to a nitrous storage module 355,
or alternatively (as indicated by reference numeral "E") to a nitrous oxide
manifold 359 shown in Figure 6.
[00144] In some embodiments, a Pressure Swing Adsorption (PSA) or
other module 352 may be provided downstream of the compressor 351 to
help remove nitrogen gas from the nitrous oxide gas stream. In some
embodiments, a PSA module 345c may be provided upstream of the
compressor 351 to help remove oxygen gas from the gas stream prior to
compression in the compressor 351.
[00145] The nitrous storage module 355 may collect nitrous oxide for
subsequent processing off-site so that the nitrous oxide may eventually be
reused.
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[00146] The nitrous oxide manifold 359 may be located on-site at the
medical facility (in some embodiments) and includes one or more storage
tanks. The nitrous oxide manifold 359 may be used to supply nitrous oxide
(e.g. via one or more pipes 361) to one or more patients 318 in one or more
operating rooms 312 during subsequent medical procedures.
[00147] In some embodiments, one or more cleaning or purification
steps may be performed at the nitrous oxide manifold 359 to ensure that the
nitrous oxide gas collected therein is suitable for subsequent usage (e.g. up
to
medically acceptable regulatory standards). For example, the purification
steps may include removal of carbon dioxide using a carbon dioxide filter
(e.g.
a soda lime filter).
[00148] By collecting and storing the nitrous oxide gases (e.g. either in
the manifold 359 or storage module 355), as opposed to venting the nitrous
oxide to atmosphere, undesired pollution tends to be reduced. Furthermore,
the nitrous oxide can be reused for subsequent medical procedures, which
may result in cost savings.
[00149] Turning now specifically to Figure 10, as shown therein the fifth
subsystem 308 is also operable to work with the first subsystem 300 for
removing at least a portion of the nitrous oxide from the exhaust gases. The
fifth subsystem 308 may include many elements similar to the second
subsystem 302, third subsystem 304, and fourth system 306, such as a
collection system 310 having a dryer 340 and one or more collectors 342 (e.g.
an adsorbent collector 342 or cryogenic collector 342a).
[00150] Similar to as described above with respect to Figure 7, and as
shown in Figure 10, at least some of the gases exiting the collectors 342 may
be fed via piping 345a to one or more reaction chambers 347 operable to
decompose the nitrous oxide into nitrogen gas and oxygen. For example, as
shown the reaction chamber 347 may be a combustion chamber that is
heated and fed a stream of combustible gas, such as methane gas (CH4) or
another hydrocarbon, to encourage the decomposition of nitrous oxide. In
other embodiments, the reaction chamber 347 may include a reaction
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chamber 347a having a heated catalyst therein for encouraging the
decomposition of the nitrous oxide.
[00151] Furthermore, as described above with respect to Figure 9, and
as shown in Figure 10, in some embodiments at least some of the gases
exiting the collectors 342 may be fed via piping 345b to one or more
compressors 351 so that they may be compressed for storage for subsequent
use. In some embodiments, a PSA module 352 may be provided downstream
of the compressor 351 to help remove nitrogen gas from the gas stream.
[00152] In some embodiments, after the PSA module 352, at least some
of the gas stream may be sent to the nitrogen manifold 359 shown in Figure 6.
In other embodiments, at least some of the gas downstream from the PSA
module 352 may be sent to a high pressure compressor 351a for additional
compression (e.g. in some examples, to approximately 745 psi, or higher or
lower pressures) for storage in a high pressure storage tank 355a. In some
embodiments, the high pressure compressor 351a may be used on its own
without the first compressor 351.
[00153] As shown, in this embodiment the fifth subsystem 308 also
includes an oxygen collector 360 for removing oxygen from the gas stream,
which may be located upstream of the reaction chamber 347. It has been
discovered that removing the oxygen (e.g. using an oxygen collector 360 as
shown) can further facilitate driving the decomposition of nitrous oxide into
nitrogen and oxygen in the reaction chambers 347. Accordingly, extracting
oxygen from the gas stream may further facilitate providing exhaust gases
with at least some of the nitrous oxide removed.
[00154] As shown, the oxygen collector 360 may be positioned
downstream of the air dryer 340 and upstream of the one or more collectors
342. In some embodiments, the oxygen collector 360 could include an
adsorbent material for removing the oxygen. In some embodiments, the
oxygen collector 360 could include a membrane separator for removing
oxygen from the gas stream. In some embodiments, the oxygen collector 360
could include a Pressure Swing Adsorption (PSA) module.
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[00155] As shown, in some embodiments the oxygen collected by the
oxygen collector 360 may be vented to atmosphere via piping 362.
[00156] In other embodiments, the oxygen can be collected for
subsequent use. For example, the oxygen may be sent via piping 364 to a
compressor 366 where it may be compressed (e.g. to approximately 50 psi).
The compressed oxygen may then be sent (as shown by reference character
"F") to an oxygen manifold 372 shown in Figure 6. The oxygen manifold 372
may in turn be used to supply oxygen (e.g. via one or more pipes 374) to one
or more patients 318 in one or more operating rooms 312 during subsequent
medical procedures.
[00157] In some embodiments, one or more cleaning or purification
steps may be performed at the oxygen manifold 372 to ensure that the
oxygen gas collected therein is suitable for subsequent usage. For example,
the purification steps may include removal of carbon dioxide using a carbon
dioxide filter (e.g. a soda lime filter).
[00158] In some embodiments, the compressed oxygen may be further
compressed in a high pressure compressor 368 (e.g. in some examples to a
pressure of around 2200 psi, or higher or lower pressures) and then stored in
a high pressure storage tank 370 for subsequent use. In some embodiments,
the high pressure compressor 368 may be used on its own without the first
compressor 366.
[00159] By collecting and storing the oxygen (e.g. either in the oxygen
manifold 372 or storage tank 370), the oxygen can be reused for subsequent
medical procedures, which may result in cost savings.
[00160] Referring now to Figures 11 and 12, illustrated therein is a
system for collecting anaesthetic agents, including a first subsystem 400 and
a second subsystem 402.
[00161] Referring to Figure 11, the first subsystem 400 may include
elements similar to the first subsystem 300 shown in Figure 6, such as the
nitrous oxide manifold 359, the oxygen manifold 372, and piping 361 and 374.
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The manifolds 359 and 373 may be in fluid communication with the second
subsystem 402 as generally indicated at reference numerals "H" and "I"
respectively, or another subsystem (e.g. subsystem 306 or subsystem 308).
[00162] The first subsystem 400 also includes an AGSS 430 (e.g. similar
to the AGSS 30 or the AGSS 330) in fluid communication via piping 413 with
one or more sources of exhaust gases, such as one or more operating rooms
412 having one or more patients 418 therein. The exhaust gases may include
nitrous oxide (N20), anaesthetic agents such as halogenated drugs (Hal.
Drugs or HD), water or moisture (H20), biological substances (1310), and in
some cases air.
[00163] One difference is that the first subsystem 400 includes at least
one filter (e.g. filters 431a, 431b, and/or 431c) between the patient 418 and
the AGSS 330 for filtering incoming exhaust gases, for example, to remove
particulates such as the biological substances. In particular, the patient 418
might expel biological substances, which might be entrained within the
exhaust gases. If left unfiltered, these biological substances might
contaminate the overall system and may interfere with system operation,
including the collection of anaesthetic agents and/or extraction of nitrous
oxide. Furthermore, health regulations might prohibit the subsequent sale or
use of collected anaesthetic agents if there are biological substances in the
collected anaesthetic agents.
[00164] As shown in Figure 11, the subsystem 400 includes one filter
431a within the operating room 412 (e.g. proximal to a mask on the patient),
and a bank of two filters 431 b and 431 c outside the operating room 412.
[00165] Providing filters inside the operating room 412 (e.g. filter 431a)
permits early filtration of exhaust gases, which might improve system
operation (e.g. collection efficiency). Furthermore, providing filters inside
the
operating room 412 might also enable medical staff to replace filters within
the
operating room 412, for example, so that a new filter may be used for each
particular patient.
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[00166] Providing filters outside the operating room 412 (e.g. filters 431 b
and 431c) might allow centralized filtration of exhaust gases, which might
reduce operating costs, and might increase filtration efficiency. Furthermore,
providing a bank of at least two filters fluidly coupled together in parallel
(e.g.
filters 431b and 431c) may provide system redundancy, and may allow one
filter (e.g. filter 431 a) to be operational while the other filter (e.g.
filter 431 b) is
being replaced.
[00167] While the filters 431 a, 431 b and 431 c are shown in Figure 11 as
having particular locations, in other embodiments, the filters may have other
locations. For example, some filters (e.g. fitters 430a and 430b) may be
located within or after the AGSS 430. The subsystem 400 may also include
more or less filters than shown.
[00168] The filters 431a, 431b, and 431c may be the same, similar, or
different types of filters. For example, one or more of the filters may be
ultra-
low particulate air (ULPA) filters, and one or more of the filters may be high
efficiency particulate air (HEPA) filters.
[00169] The filters of the first subsystem 400 are also arranged in a
plurality of stages, including, a first stage filter (e.g. filter 431a)
followed by a
second stage filter (e.g. the bank of filters 431b and 431c) downstream of the
first stage filter. Providing two or more stages of filters may improve
filtration
of exhaust gases. For example, the first stage (e.g. filter 431a) may include
a
first type of filter (e.g. a HEPA filter), which may remove certain types of
substances (e.g. a first type of particulate or biological substance), and the
second stage (e.g. filters 431b and 431c) may include a second type of filter
(e.g. a ULPA filter), which may remove other substances (e.g. a second type
of particulate or biological substance).
[00170] Another difference between the subsystem 400 and the
subsystem 300 is that the AGSS 430 includes a bank of at least two filters
430a and 430b (e.g. similar to the bank of filters 431a and 431b). This allows
one filter (e.g. filter 430a) to be operational while the other filter (e.g.
filter
430b) is being replaced, for example.
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[00171] Furthermore, each filter in the AGSS 430 may be connected to a
respective power source 433a and 433b (e.g. a vacuum pump, blower or fan).
Each power source may be turned on when the respective filter is installed
and operational, and may be turned off when the respective filter is
inoperative (e.g. being replaced).
[00172] In some embodiments, the subsystem may only include one
bank of filters (e.g. the bank of filters 430a and 430b in the AGSS 430).
[00173] The outlet of the AGSS 430 is in fluid communication with one or
more other subsystems. For example, as indicated by reference numeral "G",
in some embodiments the AGSS 430 may communicate with a second
subsystem 402 shown in Figure 12. In some embodiments, the AGSS may be
in fluid communication with other subsystems, such as the subsystems 302,
304, 306 and 308 described previously.
[00174] Referring now to Figure 12, the second subsystem 402
generally receives exhaust gases from the first subsystem 400 as indicated by
the reference numeral "G. In other embodiments, the second subsystem 402
may receive exhaust gases from other subsystems (e.g. the subsystem 300).
[00175] The second subsystem 402 may include many elements similar
to the second subsystem 302, third subsystem 304, fourth subsystem 306,
and fifth subsystem 308, such as a collection system 410 (e.g. similar to the
collection systems 10 and 310), one or more reaction chambers 347 (e.g. a
combustion chamber 347 or a catalytic reaction chamber 347a) for
decomposing nitrous oxide, one or more compressors (e.g. compressors 351
or 351a for compressing nitrous oxide, or compressors 366 or 368 for
compressing oxygen), one or more PSA modules 352 (e.g. for removing
nitrogen gas), and one or more storage tanks (e.g. a nitrous oxide storage
tank 355a or an oxygen storage tank 370). The second subsystem 402 may
also supply extracted nitrogen and/or oxygen to the first subsystem 400, or
another subsystem (e.g. the subsystem 300), as generally indicated at
reference numerals "H" and "I".
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[00176] As indicated above, the collection system 410 may include many
elements similar to the collection systems 10 and 310, such as a dryer 440,
one or more collectors 442 (e.g. an adsorbent collector 442 and/or cryogenic
collector 442a), and an oxygen collector 460.
[00177] One difference between the subsystem 402 and the subsystem
302 is that the collection system 410 also includes a condenser 480 and a
disinfection module 482 located upstream of the collectors 442.
(00178] The condenser 480 removes moisture from the exhaust gases,
and outputs a dehumidified exhaust gas. The condenser 480 may expel the
extracted moisture (e.g. through a drain 481). The condenser 480 may be a
heat-exchanger having a coolant flowing therethrough for cooling the exhaust
gases so as to condense and extract the moisture. In some embodiments, the
condenser 480 may be configured to extract a substantial portion of the
moisture, for example, so that the dryer 440 has substantially less moisture
to
extract. Extracting the moisture from the exhaust gases may also improve
efficiency of the disinfection module 482 as will be described below.
[00179] The disinfection module 482 disinfects (e.g. sterilizes) the
exhaust gases by eliminating one or more life forms such as microorganisms
(e.g. bacteria, viruses, and fungi) and outputs a disinfected exhaust gas
(e.g.
to the dryer 440). More particularly, the disinfection module 482 may
eliminate
life forms that remain in the exhaust gas after the exhaust gas has been
filtered by the upstream filters (e.g. filters 430a, 430b, 431 a, 431 b, or
431 c of
the first subsystem 400). For example, the upstream filters may remove larger
biological substances (e.g. larger spores, paramecium, bacteria, viruses,
etc),
but might not remove smaller biological substances (e.g. small bacteria and
viruses). Accordingly, the disinfection module 482 may be configured to
eliminate these smaller biological substances.
[00180] In some embodiments, the disinfection module 482 may utilize a
non-contact and non-chemical treatment such as ultraviolet (UV) radiation.
More particularly, the disinfection module 482 may utilize UV radiation having
a particular wavelength and a power level selected based on the types of
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biological substances (e.g. pathogens) that pass through the upstream filters
(e.g. filters 430a, 430b, 431a, 431b, or 431c). For example, the upstream
filters may be ULPA filters that are 99.999% effective at removing
contaminates larger than 120 nanometers, and the disinfection module 482
may apply radiation at a wavelength and power level so as to be 99.9%
effective at eliminating biological substances smaller than 120 nanometers.
As an example, the disinfection module may apply UV-C radiation in the
range of about 240-280 nanometers and at a power level above about 30,000
microwatts-second per square centimeter ( w-s/cm^2), for example, using a
low-pressure mercury vapour lamp that produces UV radiation at a
wavelength of 254 nanometers.
[00181] The disinfection module 482 may also include a UV intensity
monitor, for example, to indicate when UV lamps need to be changed.
[00182] As shown in Figures 11 and 12, the UV radiation disinfection
module 482 is located downstream of one or more filters (e.g. e.g. filters
430a,
430b, 431a, 431b, or 431c), which may improve the effectiveness of the UV
radiation disinfection module 482. In particular, the upstream filters may
remove larger contaminates, which might otherwise shield UV radiation and
prevent the radiation from eliminating smaller biological substances.
[00183] In some embodiments, the disinfection module 482 may use
other disinfection techniques, such as other forms of radiation (e.g. gamma
radiation), heat disinfection, and/or chemical treatment (e.g. ozone,
chlorine,
or hydrogen peroxide).
[00184] As shown in Figure 12, the disinfection module 482 is located
downstream of the condenser 480. As such, the disinfection module 482
receives a dehumidified exhaust gas from the condenser 480. Accordingly,
the condenser 480 can remove a substantial amount of moisture prior to
disinfecting the exhaust gas, which may increase the efficiency or
effectiveness of the disinfection module 482. For example, some life forms
travel in moisture, and it might be possible to remove some of these life
forms
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by extracting moisture from the exhaust gases. Once the moisture has been
extracted, the disinfection module 482 may have fewer life forms to eliminate.
[00185] In other embodiments, the condenser 480 may be located
downstream of the disinfection module 482. This configuration offers the
ability to disinfect the exhaust gas flow prior to condensation, which may be
desirable, for example, where regulations require treatment of any extracted
moisture prior to being discharged to a sewage system (e.g. via the drain
481).
[00186] In some embodiments, the subsystem 402 may include another
disinfection module located on the drain 481, which may be configured
specifically for water treatment so as to reduce or eliminate contaminates
flowing down the drain 481.
[00187] While some exemplary locations for the condenser 480 and
disinfection module 482 have been described, the condenser 480 and
disinfection module 482 may have other locations within the subsystem. For
example, the condenser 480 and disinfection module 482 may be located
within the operating room 412, which may allow disinfection/sterilization of
exhaust gases during localized collection of anaesthetic agents (e.g. without
a
centralized collection system).
[00188] Another difference between the subsystem 402 and the
subsystem 302 is that the collection system 410 includes a dryer regeneration
module 490 for regenerating the dryer 440 (e.g. when the dryer includes
desiccant that is full of moisture). For example, the dryer regeneration
module
490 may supply dry air to purge moisture from the dryer 440 and vent the
moisture through an exhaust (e.g. via piping 441). As shown, the dryer
regeneration module 490 may include a heated blower purge module 490a
(which may be the same as or similar to the dryer regeneration module 60).
The dryer regeneration module 490 may also include a regeneration dryer
490b for removing moisture from the main dryer 440 as described below.
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[00189] The regeneration dryer 490b may include a twin tower desiccant
dryer having a first desiccant tower 491 a, a second desiccant tower 491 b,
and
a compressor 491c for blowing air from the regeneration dryer 490 through
the main dryer 440. Each of the desiccant towers 491 a and 491 b is
selectively
operable in a drying mode for regenerating the main dryer 440, or a purging
mode so as to purge moisture from the desiccant tower.
[00190] In operation, the compressor pulls outside air through a first
desiccant tower 491a, which is operating in drying mode so as to remove
moisture from the outside air. The compressor then blows the dehumidified
outside air (e.g. purging air) through the main dryer 440 so as to regenerate
the desiccant therein. While the first desiccant tower 491a is in drying mode,
the second desiccant tower 491b is in purge mode such that a portion of the
dehumidified purging air exiting the first desiccant tower 491a flows through
the second desiccant tower 491 b so as to purge moisture from the second
desiccant tower 491 b.
[00191] When the first desiccant tower 491a is full of moisture, the
operation switches so that the second desiccant tower 491b operates in
drying mode while the first desiccant tower 491a operates in purge mode. As
such, the twin tower desiccant dryer allows continuous purging of the main
dryer 440, even when one desiccant tower is saturated with moisture. The
system may include control valves for controlling when the desiccant towers
491a and 491b are in drying mode and purge mode.
[00192] The main dryer 440 may also include a plurality of dryers fluidly
coupled in parallel (e.g. similar to the twin tower desiccant dryer of the
regeneration dryer 490b). For example, a first dryer (e.g. a first desiccant
tower 440a) may remove moisture from the exhaust gases while the
regeneration module 490 (e.g. the regeneration dryer 490b) regenerates or
purges moisture from a second dryer (e.g. a second desiccant tower 440b).
[00193] Then, when the first desiccant tower 440a is saturated with
moisture, the operation may switch such that the regeneration module 490
begins regenerating the first desiccant tower 440a while the second desiccant
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tower 440b removes moisture from the exhaust gases. The system may
include control valves for controlling when the two desiccant towers 440a and
440b are in operation (i.e. removing moisture from the exhaust gases) or
being purged by the regeneration module 490.
[00194] In some embodiments, air supplied from the regeneration
module 490 (e.g. the regeneration dryer 490b) may also be used to operate
one or more pneumatically controlled valves within the system (e.g. valves 50,
70, 72, 84, 86, 88 described previously with respect to the collection system
10). More particularly, the compressor 491c of the regeneration dryer 490b
may supply pressurized air for operating the control valves.
[00195] The collection system 410 may also include a bank of filters
(e.g. filters 492a and 492b) between the dryer 440 and the collectors 442.
This bank of filters offers another opportunity to remove contaminants and
other particulates from the exhaust gases prior to entering the collectors
442.
For example, the filters 492a and 492b may remove particulates such as
desiccant particles entrained in the exhaust gases after passing through the
dryer 440. The filters 492a and 492b might also remove biological substances
that remain in the exhaust gases after being treated by the disinfection
module 482. In particular, the filters 492a and 492b may filter out
microorganisms that were killed by the disinfection module 482.
[00196] In some embodiments, the filters 492a and 492b may be located
in other positions, for example, upstream of the oxygen collector 460 or
upstream of the dryer 440.
[00197] Referring now to Figures 13 and 14, illustrated therein is another
system for collecting anaesthetic agents, including a first subsystem 500 and
a second subsystem 502.
[00198] Referring to Figure 13, the first subsystem 500 is similar in many
respects to the first subsystem 400 shown in Figure 11. One difference is that
the filters 431b and 431c are located downstream of the AGSS 430.
Positioning the filters after the AGSS 430 may increase filtration efficiency,
for
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example, because the exhaust gases leaving the AGSS 430 are under
positive pressure, and the filters may be more efficient when filtering
exhaust
gases under positive pressure (e.g. approximately 3 psi) as opposed filtration
under negative pressure upstream of the AGSS (e.g. 12-20 inches-Hg).
[00199] Another difference is that the subsystem 500 identifies carbon
dioxide (C02) as a substance within the exhaust gases. It will be understood
that previous embodiments may also include carbon dioxide within the
exhaust gases even if not expressly identified.
[00200] Referring now to Figure 14, the second subsystem 502 is similar
in many respects to the second subsystem 402 shown in Figure 12. One
difference is that the disinfection module 482 is located further downstream
within the collection system 410 (i.e. between the filters 492a and 492b and
the collectors 442). Positioning the disinfection module 482 further
downstream may increase the effectiveness of the disinfection module 482,
for example, because other system components might remove substances
that would otherwise interfere with the disinfection process. In particular,
particles such as water molecules might block UV radiation that is used to
disinfect the exhaust gases. Accordingly, it might be desirable to remove
these substances (e.g. using dryers, filters, membrane separators and the
like) prior to disinfecting the exhaust gas.
[00201] Another difference is that the second subsystem 502 includes a
number of devices and processes for drying the exhaust gases prior to
collection. For example, as described previously with respect to Figure 12, at
least some of the exhaust gases may be fed to the dryer 440 (e.g. via piping
520a) for removing moisture.
[00202] Furthermore, in some embodiments, at least some of the
exhaust gases may be fed to a compressor 530 (e.g. via piping 520b) for
increasing the pressure of the exhaust gases. For example, the compressor
530 may receive the exhaust gases at a low pressure (e.g. at approximately 3
psi) and may output the exhaust gases at a high pressure (e.g. at
approximately 80-120 psi). The compressor 530 may be a variable speed
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compressor (e.g. as shown in Figure 14) or another type of compressor such
as a fixed speed compressor.
[00203] The high pressure exhaust gases leaving the compressor 530
may be fed to one or more dryers. For example, at least some of the high
pressure exhaust gases may be fed to a desiccant dryer 540 (e.g. similar to
the dryers 40, 340, and 440). The dryer 540 may be more efficient at
removing moisture from high pressure exhaust gases in comparison to low
pressure exhaust gases, for example, because the flow rate of the exhaust
gases through the dryer 540 can be increased, or because the size of the
dryer 540 can be reduced, or both.
[00204] Furthermore, at least some of the high pressure exhaust gases
leaving the compressor 530 may be fed to a membrane dryer 542. The
membrane dryer 542 generally includes a porous membrane separator that
removes water vapor from the high pressure exhaust gases, for example,
based on selective adsorption of water molecules. Similar to the desiccant
dryer 540, the membrane dryer 542 may be more efficient at removing
moisture from high pressure exhaust gases in comparison to low pressure
exhaust gases.
[00205] As shown, the portion of the exhaust gases leaving the dryer
440 and the desiccant dryer 540 may pass through a drug concentrator 560
and then through a set of filters 492a and 492b. The filters 492a and 492b
may filter out desiccant particles that may be entrained in the exhaust gases
after passing through the dryers 440 and 540.
[00206] The drug concentrator 560 may remove substances from the
exhaust gases (e.g. oxygen, carbon dioxide and the like) so as to increase the
concentration of anaesthetic agents prior to collection using the collectors
442. In some embodiments, the drug concentrator 560 may include an
adsorbent material, a membrane separator (e.g. similar to the oxygen
collector 360), or a PSA module. The substances collected by the drug
concentrator 560 may be vented to atmosphere (e.g. via piping 462), or may
be collected for subsequent use (e.g. oxygen may be routed to the
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compressor 366 via piping 364 for storage in the storage tank 370, or for
resupply to patients via the oxygen manifold 372).
[00207] While Figure 14 refers to a few specific examples of drug
concentrators, the drug concentrator 560 is more generally any device that
removes a substance from the exhaust gas prior to collection of the
anaesthetic agents (e.g. to increase the concentration of the anaesthetic,
agent within the exhaust gas). Accordingly, in some embodiments, the drug
concentrator 560 may include filters (e.g. filters 430a, 430b, 431 a, 431b,
431c,
492a, 492b, etc), dryers (e.g. dryers 440, 540, 542, or the condenser 480),
membrane separators, PSA modules, and the like.
[00208] Similar to the exhaust gases leaving the dryer 440 and the
desiccant dryer 540, the portion of the exhaust gases leaving the member
dryer 542 may also flow through a drug concentrator 562, which may be the
same as, or similar to, the drug concentrator 560. In some embodiments, the
membrane dryer 542 and the drug concentrator 562 may be incorporated into
a single membrane separator that removes both water molecules and other
gases such as oxygen and carbon dioxide.
(00209] While the exhaust gases leaving the membrane dryer 542 pass
through a drug concentrator, it can be seen that these exhaust gases do not
pass through any additional filters (e.g. like the filters 492a and 492b). The
filters may be omitted, for example, because the membrane dryer 542 does
not use desiccant particles that might otherwise contaminate the exhaust
gases (whereas the dryers 440 and 540 might introduce desiccant particles
and it might be desirable to filter out those desiccant particles).
[00210] In some embodiments, the condenser 480 may be located after
the compressor 530, which may increase the efficiency of the condenser 480.
For example, the condenser 480 may be more efficient at removing moisture
from high pressure exhaust gases (approximately 80-120 psi) in comparison
to low pressure exhaust gases (e.g. approximately 3 psi) because the water
vapor in the high pressure exhaust gases has a higher condensation
temperature (i.e. a higher dew point). A higher condensation temperature
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allows the condenser 480 to operate at a higher temperature (e.g. without the
need to refrigerate the exhaust gases), which may increase the efficiency of
the condenser 480.
[00211] Another difference between the subsystem 502 and the
subsystem 402 is that the gas products exhausted by the collectors 442 may
be sent via piping 345a to another type of reaction chamber 347b for
decomposing nitrous oxide within the gas products. In particular, the reaction
chamber 347b may include a plasma arc conversion module that feeds the
gas products through a high temperature plasma torch so as to decompose
the nitrous oxide into nitrogen and oxygen.
[00212] While some of the embodiments described above may refer to
collecting or reclaiming halogenated drugs, the apparatus, systems and
methods described herein may generally be used for the collection of various
types of anaesthetic agents, including halogenated drugs and other agents.
[00213] Although the above description provides examples of one or
more methods, systems and apparatuses, it will be appreciated that other
methods, systems and apparatuses may be within the scope of the present
description as interpreted by one of skill in the art.
